LED lamps using LEDs (light emitting diodes) are used in various fields such as interior lights, and backlights for liquid crystal display devices and the like. Because an LED lamp can reduce power consumption more outstandingly than an electric discharge lamp, cold cathode tube and the like, attempts are being made to apply the LED lamp to various fields. One of typical examples includes automobile lamps. Examples of these automobile lamps include a headlight, side lamp, and back lamp (brake lamp).
For example, a headlight serves to illuminate a wide area with light from an LED by using a reflection plate, diffusion plate, scattering plate and the like. In order to illuminate a wide area with LED light, it is effective to improve reflection efficiency and diffusion efficiency by registering the positions of a reflecting plate, diffusion plate and the like with the position of an LED. Further, a method of raising luminous intensity by mounting a plurality of LEDs is effective (for example, Patent Literature 1). In the meantime, an LED chip is a very small luminous element having a size of about 1 mm×1 mm square. For this, if the positions cannot be exactly registered, satisfactory reflection efficiency and diffusion efficiency cannot be obtained.
Further, LEDs generate heat when they emit light and therefore, there is a demand for a substrate having high heat radiating ability. Moreover, vehicles are, of course, vigorously vibrated and it is therefore desired to take anti-vibration measures to protect a head lamp to be mounted thereon. For example, a resin substrate has low strength and therefore needs a reinforcing member.
Further, Patent Literature 2 discloses anti-vibration measures using a heat pipe having a first bending section and a second bending section. Vibration can be absorbed by using such a heat pipe. However, a heat pipe having such a complex form with the first and second bending sections is required, which is a cause of cost-up.
Further, position registration is also important for semiconductor devices and solar cell devices besides LED chips. A deviation of the mounting position of a device on a substrate is a cause of defects of electronic parts.